檢索所有沒有登錄用戶從MySQL表（SQL查詢）

Question

我有如下2個表：

+-------------+-----------+--------------+-------------------------------+ 
|        v3_customer        | 
+-------------+-----------+--------------+-------------------------------+ 
| customer_id | firstname | lastname |    email    | 
+-------------+-----------+--------------+-------------------------------+ 
|   1 | Piet  | Pizza  | piet.pizza@example.com  | 
|   2 | Klaas  | Hein   | klaas.hein@example.com  | 
|   3 | Henk  | Crowdcontrol | henk.crowdcontrol@example.com | 
+-------------+-----------+--------------+-------------------------------+ 

+-------------+-------------+---------------+ 
|   v3_customer_activity   | 
+-------------+-------------+---------------+ 
| activity_id | customer_id |  key  | 
+-------------+-------------+---------------+ 
|   1 |   1 | login   | 
|   2 |   1 | order_account | 
|   3 |   2 | login   | 
+-------------+-------------+---------------+ 

我要的是選擇已經沒有登錄的所有客戶（注意登錄鍵v3_customer_activity）。所以在這種情況下，這將是客戶customer_id：3

我正在使用mysql數據庫。

我曾嘗試使用下面的查詢嘗試：

SELECT DISTINCT v3_customer.customer_id, v3_customer.firstname, v3_customer.lastname, v3_customer.email FROM `v3_customer` JOIN v3_customer_activity ON v3_customer.customer_id = v3_customer_activity.customer_id WHERE v3_customer.customer_id != (SELECT v3_customer_activity.customer_id FROM v3_customer_activity) 

在此希望它會在子查詢中發現的行之間循環。 這導致了一個錯誤，告訴我一個子查詢可能不包含多行。

TL; DR

我想要的是檢索v3_customer每一個客戶誰不是在表v3_customer_activity

Answer 1

上市試試這個：

select v3_customer.* from v3_customer 
left join v3_customer_activity on v3_customer.customer_id=v3_customer_activity.customer_id 
where v3_customer_activity.customer_id is null; 

LEFT JOIN v3_customer表v3_customer_activity和不匹配的過濾器記錄。

Answer 2

select v3_customer.* from v3_customer 
where v3_customer.customer_id not in (SELECT v3_customer_activity.customer_id FROM v3_customer_activity)